DEFENCE Force chief David Hurley has admitted mistakes were made when Australian border protection vessels breached Indonesian sovereignty six times while trying to turn back asylum seekers.

However, he is confident the incursions won’t happen again.

A Defence and Customs review found Australian ships inadvertently entered Indonesian territorial waters six times between December last year and January 2014, in a series of events that has placed further strain on relations between the two countries.

General Hurley said Defence had yet to determine “exactly why some decisions were made’’.

“But frankly, from our point of view we’ve acknowledged the mistake, we’ve got to take that on chin, get on with the job we’re doing, and a job I think that’s achieving results,’’ he told ABC Radio today.

The review made five recommendations to ensure the territorial incursions didn’t occur in the future, including reviewing operational training for border protection officers, policy and procedure documents.

Asked if he was confident it wouldn’t happen again, General Hurley said: “Yes”.

While the Indonesian government was disappointed by the incursions, it understood how they had occurred.

“There was an agreement that this was an accurate summary of what had occurred, and they’re accepting of that explanation,’’ General Hurley.

The Defence and Customs review was released yesterday.

Two navy frigates, HMAS Stuart and HMAS Parramatta were responsible for four breaches and Customs vessels the other two.

The review found that the breaches were contrary to government policy and the direct instructions of Operation Sovereign Borders headquarters in Canberra.

That means the Navy ships simply strayed into Indonesia’s 12-mile nautical boundary despite being fitted with sophisticated GPS systems accurate to within one-metre anywhere on the surface of the earth.

Those breaches occurred during tow-back operations when the ships were trying to get asylum seeker vessels as close as possible to a landfall.

However Navy sources believe that the errors were a combination of poor navigation and unclear instructions from Operation Sovereign Borders under the command of Lieutenant General Angus Campbell.

The review found that the breaches were inadvertent and contrary to the government’s aim of conducting operations without compromising Indonesian sovereignty.

It acknowledged that the Abbott Government had formally apologised to Indonesia and that both the Chief of Defence and head of Customs had accepted the reviews findings.

It is understood that just the executive summary of the review will be released publicly.

Revelations that Australian vessels had breached Indonesian sovereignty prompted an angry response from Jakarta and followed damaging revelations that Australian agencies had spied on the Indonesian President Susilo Bambang Yudhoyono, his wife and senior colleagues.

The incursions were discovered on January 15 and revealed by Immigration Minister Scott Morrison two days later.

Australia has apologised to Indonesia for the unintentional incursions.

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